BillFitzmaurice.info

Hi all, I did sound for a musical this last weekend and now that I am finally able to sit down and reflect I have a few questions about wireless microphones.

To start off, When I first started using the wireless microphones I did a lot of reading about intermodulation. It was from there that I found out that if there are too many microphones with their frequencies too close to each other that it can cause drop outs and other unwanted problems. So with that I found a link on the companies website that allowed me to calculate the frequencies for up to 20 wireless packs.

Here is my questions.

1. If the website calculated these frequencies and deemed them to not have any problems between packs, why did I still have drop outs and pops?

2. Is it possible that the phones that were in the hall were able to interfere with the wireless microphones I had on stage?

3. I had some microphones that would distort even though all my gain levels were well below the distortion levels. The levels on the packs were down as far as they would go and when the vocalists would belt it would sound distorted.

4. The man playing the main Character of the musical was very dynamic which prompted me to place a compressor on his channel. First off that worked awesomely. The problem I was getting from his was that his mic would often sound fuzzy as if a radio station was just not quite on the right frequency on a home stereo...

Any answers would be greatly appreciated. Also the new Bill Fitzmaurice Tops were fantastic in this concert hall.

Check out RF Guru. Works wonderfully even with many makes and models of wireless mics. Will help programming the proper frequency in relation to all the mics.

Research proper antenna placement as well. That is probably the biggest mistake made when using wireless systems. Placement of the transmitter pack makes a big difference as well. Water bags (human beings) are the biggest enemy when it comes to good wireless operation.

Did the company's website take into account your geographical location? If not, the calculations would not have included local TV stations which also play into the mix.

+1 to RF Guru. It solved a lot of problems for me.

As for the distortion and fuzzies... what systems and mic elements were you using?

The main mics were AudioTechnica 3000's. As for taking into account the location I did find out what frequencies were not available via the site as well. But the bodies makes sense. I have looked into RF guru and I don't know if that is something that I can afford at this moment being I don't work with that many all that often.

bradn7 wrote:The main mics were AudioTechnica 3000's. As for taking into account the location I did find out what frequencies were not available via the site as well. But the bodies makes sense. I have looked into RF guru and I don't know if that is something that I can afford at this moment being I don't work with that many all that often.

The RF Guru demo is fully functional, you just have to rebuild your rig every time (no saving or recalling).

AT3000s aren't bad systems, but there are a couple of things you can do to maximize their efficiency. First, they have a "Hi/Lo" power mode switch. They should ALWAYS be on HI power... its 30mw vs 10mw. Second, with that many wireless systems, you should be using antenna distribution. When there are a bunch of the stubby antennas in one place, the antennas themselves can cause reflections and nulls, and thus you can have intermodulations. in order to do this. look at the ATW-DA49 antenna distribution kit. Each one will support four recievers, and I believe you can use one unit to distribute out a single set of antennas to multiple DA49s if you have more than four recievers. You'll want to get the audio technica powered antennas as well. The DA49s will also power your recievers, so it will clean up your wiring dramatically.

Now... all that's going to cost you a bit. The poor man's solution is to put the recievers near the stage and space them out (at least a receiver's distance between each pair). This takes a lot of space and it means you can't see the displays, but it does help sort out random intermod problems sometimes.

Ok. That would make a lot of sense. We were well over 80 feet away from the performers. But all in all I thought it was a great performance.

The wireless kits we used were purchased a few years ago by a group in Town. They loaned them and when I recieved them they were all sorts of messed up. I was rather happy with as far as I got them to. I will inform them to improve their performance to add the aforementioned items. Thank you!

bradn7 wrote:The wireless kits we used were purchased a few years ago by a group in Town. They loaned them and when I recieved them they were all sorts of messed up.

When my wireless kits go out, they have a sticker on them detailing what's in the kit, and in very nice terms, it basically says: "You break it or lose it, you bought it." My kits stay nice.